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1.
Apunts, Med. esport (Internet) ; 55(206): 53-61, abr.-jun. 2020. graf, tab
Artículo en Inglés | IBECS | ID: ibc-ET2-5892

RESUMEN

This study examines the effects of two strength training (ST) programs, one based on mean propulsive velocity (MPV) and another under the traditional method, the % one-repetition maximum (1RM), on neuromuscular performance and muscle composition in girls who play soccer. Fifty players with an average age of 13.6 ± 1.2 years participated in the study and were randomly assigned into three groups: a maximal execution velocity training group (VG, n = 15), a maximal strength group (RMG, n = 13), and a control group (CG, n = 18). The study was developed for a period of twelve weeks during regular team training to prepare for the season. The VG and RMG groups performed additional strength or muscle power training three times a week, including movements of full squat and pedaling on a cycle ergometer. The two types of training groups and the control group exhibited significant gains. However, the greatest increases were achieved with VG training, with significant increases (p < 0.000) in maximal strength, (p < 0.000) squat power, (p < 0.000) velocity over 30 m, (p < 0.000) cycle ergometer power, and (p < 0.008) lower limb muscle mass. Statistically significant differences were observed between VG and RMG in countermovement jump (CMJ) (p < 0.008) and squat power (p < 0.01) tests, between VG and CG in CMJ (p < 0.01), squat power (p < 0.000), and maximal squat strength (p < 0.000), and between RMG and CG in maximal squat strength (p < 0.000) only. These findings might indicate that high-velocity ST can be performed simultaneously with regular training to improve the explosive actions of soccer players


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Asunto(s)
Humanos , Femenino , Niño , Adolescente , Rendimiento Atlético/fisiología , Fútbol/fisiología , Fuerza Muscular/fisiología , Entrenamiento de Intervalos de Alta Intensidad/métodos , Unión Neuromuscular/fisiología , Análisis de Varianza , Entrenamiento de Resistencia/métodos
2.
MHSalud ; 17(1): 49-63, ene.-jun. 2020. tab, graf
Artículo en Español | LILACS | ID: biblio-1091030

RESUMEN

Resumen El objetivo de este estudio fue comparar los efectos de un calentamiento con aplicación de saltos cargados y sin carga sobre el tiempo en sprint de 20 metros, saltos horizontales y saltos verticales en jugadores juveniles de balonmano. La muestra estaba conformada por 13 jugadores de balonmano (16,2 ± 1,3 años) de San Carlos. Se realizó un estudio experimental con un diseño crossover aleatorizado. Se aplicaron 3 protocolos de calentamiento distintos, que implicaban correr más estiramientos dinámicos (CE); correr, estiramientos dinámicos y saltos (CES), y, finalmente, correr, estiramientos dinámicos y saltos cargados con el 8 % de su peso corporal (CESH). Para las evaluaciones pre- y poscalentamiento, se utilizó un test de salto contramovimiento (CMJ), salto horizontal (SH) y sprint de 20 metros cronometrado. Los resultados muestran diferencias significativas entre pre- y postest para los 3 grupos en el SH (diferencias para CES: 0,09 ± 0,12; CESH: 0,12 ± 0,16 y CE: 0,07 ± 0,16), mientras que solo CES y CESH mejoraron significativamente la altura en CMJ y tiempo en el sprint de 20 metros (diferencia para CMJ: 2,95 ± 0,56 y 3,50 ± 0,73; y sprint de 20 m: 0,29 ± 0,31 y 0,20 ± 0,26, respectivamente). En conclusión, un calentamiento que incluye distintos tipos de saltos es eficaz para mejorar SH, CMJ y velocidad en 20 metros. Es necesario realizar más investigación, para determinar beneficios específicos de saltos con halteras de manos que mejoren el rendimiento físico.


Abstract The aim of this study is to compare the effects of a warm-up with the application of loaded and unloaded jumps on the performance in speed, horizontal jumps and vertical jumps in youth handball players. The sample consists of 13 handball players from the city of San Carlos (16.2 ± 1.3 years). An experimental study with a randomized crossover design carried out. 3 different heating protocols applied, which involved running more dynamic stretching (RS), running, dynamic stretching and jumping (RSJ) and finally running, dynamic stretching and jumps loaded with 8% of your body weight (RSLJ). For the pre- and post-warming assessments, a countermovement jump test (CMJ), horizontal jump (HJ) and were used through a 20-meter timed to sprint test. The results show significant differences between pre- and post-test for the 3 groups in the SH (difference for CES: 0.09 ± 0.12; CESH: 0.12 ± 0.16 and EC: 0.07 ± 0.16), while only CES and CESH significantly improved the height in CMJ and sprint time of 20 meters (difference for CMJ: 2.95 ± 0.56 and 3.50 ± 0.73; and sprint 20 meters: 0.29 ± 0,31 and 0.20 ± 0.26, respectively). In conclusion, a warm-up that includes different types of jumps is effective in improving SH, CMJ and speed in 20 meters. More research needed to determine specific benefits of handheld loading jumps to improve physical performance.


Resumo O objetivo deste estudo foi comparar os efeitos de um aquecimento com a aplicação de saltos acompanhado e não acompanhados de pesos, em velocidade de 20 metros de tempo, saltos horizontais e saltos verticais em jogadores de handebol juvenil. A amostra foi constituída por 13 jogadores de handebol (16,2±1,3 anos). Foi realizado um estudo experimental com um desenho cruzado randomizado. Foram aplicados três protocolos diferentes de aquecimento, envolvendo alongamentos mais dinâmicos (CE), alongamentos e saltos dinâmicos (CES) e, finalmente, alongamentos e saltos dinâmicos (CESH), carregados com 8% do seu peso corporal. Para as avaliações antes e depois do aquecimento, foram utilizados um salto contra movimento (CMJ), salto horizontal (SH) e um sprint temporizado de 20 metros. Os resultados mostram diferenças significativas entre o pré e após a prova para os três grupos na HAS (diferenças para o CES: 0,09±0,12; CESH: 0,12±0,16 e CE: 0,07±0,16), enquanto apenas o CES e o CESH melhoraram significativamente a altura na CMJ e o tempo de velocidade de 20 metros (diferença para CMJ: 2,95±0,56 e 3,50±0,73; e velocidade de 20 metros: 0,29±0,31 e 0,20±0,26 respectivamente). Em conclusão, um aquecimento que inclua diferentes tipos de saltos é eficaz na melhoria do SH, CMJ e velocidade em 20 metros. Mais pesquisas são necessárias para determinar os benefícios específicos de saltar com pesos para melhorar o desempenho físico.


Asunto(s)
Humanos , Chile , Rendimiento Atlético , Atletas , Ejercicio de Calentamiento
3.
Int. j. morphol ; 38(3): 545-551, June 2020. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1098285

RESUMEN

SUMMARY: The objective of this research is to relate the performance in three vertical jump events with morphological variables of the foot and stature. A total of 177 practitioners of 12 sporting events aged 24.5 ±8.0 years, with 71.01 ±13.00 kg of body mass, 1.71±0.09 m height, and BMI of 24.29±3.24 kg·m-2 were evaluated with an anthropometer in terms of foot length (FL), forefoot width (FW), navicular height (NH), and hindfoot width (HW). These variables were normalized to the height of the subjects. From the footprint record the arch index (AI) was obtained, which indicates the morphology of the medial longitudinal foot arch (MLFA). Performance was evaluated in three vertical jump events: countermovement jump (CMJ), squat jump (SJ), and drop jump (DJ), recording the height reached. FL, FW and HW show a weak positive correlation (r<0.4; p<0.05) with the heights achieved in the three types of jump. The stature is strongly associated with FL, FW and HW (r=0.8; r=0.7 and r=0.6; respectively; p<0.05) and with the height in CMJ, SJ, and DJ (r=0.37; r=0.41 and r=0.32, respectively, p<0.05). The only normalized morphological foot variable that maintained consistency in the correlations analysis was the normalized foot length (NFL) with CMJ (r = 0.2, p<0,05). The subjects whose left foot length was equivalent to 14 % of the stature jumped 27.94 ±6.63 cm, those with 15 % jumped 30.96 ±7.4 cm, and those with 16 % jumped 31.03 ±7.8 cm. FL, FW, HW, and stature are moderately correlated with performance in vertical jump events. However, after discarding the stature of the subjects, only the foot length maintained its relation with performance in CMJ.


RESUMEN: El objetivo de esta investigación fue relacionar el rendimiento en salto vertical con variables morfológicas del pie y estatura. 177 practicantes de 12 disciplinas deportivas de 24,5 ±8,0 años; 71,01 ±13,00 kg; 1,71 ±0,09 m, e IMC de 24,29 ±3,24 kg•m-2 fueron evaluados con un antropómetro obteniendo longitud de pie (FL), ancho de antepié (FW), altura navicular (NH) y ancho de retropié (HW). Estas variables fueron normalizadas a la estatura. Se midió la huella plantar obteniendo el índice del arco (AI), el cual indica la morfología del arco plantar longitudinal medial (MLFA). El rendimiento fue evaluado en tres pruebas de salto: salto con contramovimiento (CMJ), sentadilla con salto (SJ) y salto desde caída (DJ), registrando la altura alcanzada. FL, FW y HW mostraron una débil correlación positiva (r<0,4; p<0,05) con la altura alcanzada en los tres saltos. La estatura se asocia con FL, FW y HW (r=0,8; r=0,7 y r=0,6; respectivamente; p<0,05) y con la altura en CMJ, SJ y DJ (r=0,37; r=0,41 y r=0,32, respectivamente, p<0,05). La única variable normalizada del pie que mantuvo consistencia en el análisis de correlaciones fue la longitud del pie normalizada (NFL) con CMJ (r=0,2; p<0,05). Los sujetos cuyo pie tiene una longitud equivalente al 14 % de la estatura saltaron 27,94 ±6,63 cm, los que equivalen al 15 % saltaron 30,96 ±7,4 cm y quienes tuvieron un pie equivalente a un 16 % de la estatura saltaron 31,03 ±7,8 cm. FL, FW, HW y la estatura se correlacionan moderadamente con el rendimiento en salto vertical. Sin embargo, después de descartar la estatura de los sujetos, solamente la longitud del pie mantiene su relación con el rendimiento en CMJ.


Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Adulto Joven , Rendimiento Atlético/fisiología , Pie/anatomía & histología , Movimiento
4.
Medicine (Baltimore) ; 99(21): e20418, 2020 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-32481345

RESUMEN

BACKGROUND: Isokinetic training (IKT) and core stabilization training (CST) are commonly used for balance training in musculoskeletal conditions. The knowledge about the effective implementation of these training protocols on sports performances in university football players with chronic low back pain (LBP) is lacking. OBJECTIVE: To find and compare the effects of IKT and CST on sports performances in university football players with chronic LBP. DESIGN: Randomized, double-blinded controlled study. SETTING: University hospital. PARTICIPANTS: Sixty LBP participants divided into isokinetic group (IKT; n = 20), core stabilization group (CST; n = 20), and the control group (n = 20) and received respected exercises for 4 weeks. OUTCOME MEASURES: Clinical (pain intensity and player wellness) and sports performances (40 m sprint, 4 × 5 m sprint, submaximal shuttle running, counter movement jump, and squat jump) scores were measured at baseline, after 4 weeks, 8 weeks, and 3 months. RESULTS: Four weeks following training IKT group shows more significant changes in pain intensity and player wellness scores than CST and control groups (P ≤ .001). Sports performance variables (40 m sprint, 4 × 5 m sprint, submaximal shuttle running, counter movement jump and squat jump) scores also show significant improvement in IKT group than the other 2 groups (P ≤ .001). CONCLUSION: This study suggests that training through IKT improves pain intensity and sports performances than CST in university football players with chronic LBP.


Asunto(s)
Rendimiento Atlético/normas , Dolor de la Región Lumbar/terapia , Dolor/clasificación , Modalidades de Fisioterapia/normas , Rendimiento Atlético/estadística & datos numéricos , Dolor Crónico/psicología , Dolor Crónico/terapia , Método Doble Ciego , Hospitales Universitarios/organización & administración , Hospitales Universitarios/estadística & datos numéricos , Humanos , Dolor de la Región Lumbar/psicología , Masculino , Dolor/prevención & control , Modalidades de Fisioterapia/psicología , Modalidades de Fisioterapia/estadística & datos numéricos , Entrenamiento de Resistencia/métodos , Entrenamiento de Resistencia/normas , Entrenamiento de Resistencia/estadística & datos numéricos , Fútbol/lesiones , Fútbol/psicología , Adulto Joven
5.
Rev Assoc Med Bras (1992) ; 66(2): 180-186, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32428153

RESUMEN

OBJECTIVE: The current study aimed to examine the body composition of adult male ultra-trail runners (UTR) according to their level of participation (regional UTR-R, vs. national UTR-N). METHODS: The sample was composed of 44 adult male UTR (aged 36.5±7.2 years; UTR-R: n=25; UTR-N: n=19). Body composition was assessed by air displacement plethysmography, bioelectrical impedance, and dual-energy X-ray absorptiometry. In addition, the Food Frequency Questionnaire (FFQ) was applied. A comparison between the groups was performed using independent samples t-test. RESULTS: Significant differences between groups contrasting in the competitive level were found for chronological age (in years; UTR-R: 38.8±8.2 vs. UTR-N: 33.5±4.1); body density (in L.kg-1; UTR-R: 1.062±0.015 vs. UTR-N: 1.074±0.009); and fat mass (in kg; UTR-R: 12.7±6.8 vs. UTR-N: 7.6±2.7). CONCLUSION: UTR-N were younger, presented higher values for body density, and had less fat mass, although no significant differences were found for fat-free mass. The current study evidenced the profile of long-distance runners and the need for weight management programs to regulate body composition.


Asunto(s)
Composición Corporal/fisiología , Carrera/fisiología , Absorciometría de Fotón , Adulto , Antropometría , Atletas , Rendimiento Atlético/fisiología , Impedancia Eléctrica , Humanos , Masculino , Pletismografía/métodos , Valores de Referencia , Encuestas y Cuestionarios , Factores de Tiempo
6.
Int J Sports Med ; 41(7): 450-460, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32396967

RESUMEN

This study aimed to investigate the relationship between mechanical parameters from the Running-based Anaerobic Sprint Test (RAST2×17.5), agility performance from the Illinois Agility Test (IAT) and all-out 30-second tethered running (AO30) in college futsal athletes. It also investigates whether these protocols are capable of identifying differences between sexes. Twenty subjects were evaluated. The IAT was applied on a specific course and performance was considered as the total time (T.T). The RAST2×17.5 consisted of six maximum efforts in a shuttle exercise of 2x17.5 m per bout. The AO30 was conducted under maximal effort on a non-motorized treadmill. Maximum, mean and minimum power were determined for RAST2×17.5 and AO30. Mean power from RAST2×17.5 was inversely and significantly correlated to T.T regardless of sex (male: r=-0.76; p=0.010; female: r=-0.89; p=0.010). A similar association was noticed for maximum power for females (r=-0.94; p=0.001). The AO30 maximum and mean power were significantly correlated with T.T (male: r=-0.67; p=0.031 and r=-0.66; p=0.035, respectively; female: r=-0.64; p=0.046 and r=0.66; p=0.035, respectively). Maximum power from RAST2×17.5 and AO30 were significantly correlated (male: r=0.68; p=0.030; female: r=0.72; p=0.019). Our results reinforce the adoption of field-based tests like RAST2×17.5 and IAT for futsal, since significant relationships among these parameters and AO30 results were obtained. Moreover, these protocols differentiated male and female athletes by mechanical and agility parameters, proving their application under specific field evaluation.


Asunto(s)
Rendimiento Atlético/fisiología , Prueba de Esfuerzo/métodos , Destreza Motora/fisiología , Deportes/fisiología , Rendimiento Atlético/psicología , Femenino , Humanos , Masculino , Consumo de Oxígeno , Carrera/fisiología , Factores Sexuales , Deportes/psicología
7.
Int. j. morphol ; 38(2): 328-335, abr. 2020. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1056443

RESUMEN

The aim of this research is to investigate the correlation of morphological characteristics, that is, body composition characteristics with the competitive performance of female basketball players of cadet (U16) age, in general and depending on the position played in the basketball team. The research involved female basketball players from the U16 section of the three best basketball clubs from the First Cadet League of Serbia (N = 30). This research consisted of measuring the characteristics of body composition, as a space of independent variables and the analysis of competitive activities where the dependent variable represents the level of achieved competitive performance. Based on the results of the Pearson Correlation Analysis, which was made for determining the degree of connection between the dependent variable and the independent variables, it can be seen that general level competitive performance is associated with the variables: percentage skeletal muscle mass, index of hypokinesy and protein-fat index. Viewed from the point of the position played in the team, the statistically significant relationship between the independent and the dependent variable was recorded only in the forwards position. Competitive and more successful forward players are distinguished by a small percentage of body fat mass, a higher percentage of muscle mass, a smaller hypokinesy index and a larger protein-fat index. The practical application of this research can be seen in the control system of applied training work, then selection, as well as in the creation of a model for morphological characteristics of players in the cadet (U16) age.


El objetivo del estudio fue investigar la correlación entre las características morfológicas, es especial, las características de la composición corporal y el rendimiento competitivo de jugadoras de baloncesto cadetes, en general y en cada posición en el equipo. La investigación incluyó a las jugadoras de baloncesto femenino U16 de los tres mejores clubes de Primera Liga de Cadetes de Serbia (N = 30). Esta investigación consistió en medir las características de la composición corporal, como un espacio de variables independientes, y el análisis de actividades competitivas, donde la variable dependiente representa el nivel de rendimiento competitivo alcanzado. Sobre la base de los resultados del análisis de coeficiente de correlación de Pearson, que se realizó con el propósito de determinar el grado de conexión entre la variable dependiente y las variables independientes, se pudo observar que, en general, el rendimiento competitivo está vinculado a las variables: porcentaje de masa muscular esquelética, índice de hipocinesia e índice proteínagrasa. Desde el punto de vista de posiciones dentro de un equipo de baloncesto, la relación estadísticamente importante entre la variable independiente y la variable dependiente ha sido registrada solamente en la posición de delantero. Las jugadoras delanteras más exitosas y competitivas se distinguen por un bajo porcentaje de grasa en su masa corporal, así como un mayor porcentaje de masa muscular, un índice de hipocinesia más bajo y un índice proteína-grasa más alto. El uso práctico de esta investigación se puede ver en el sistema de control del trabajo de entrenamiento aplicado, luego en la selección, así como en la creación de modelos de características morfológicas de jugadoras en la categoría cadetes (U16).


Asunto(s)
Humanos , Femenino , Adolescente , Baloncesto , Antropometría , Rendimiento Atlético , Modelos Lineales
8.
Nutrients ; 12(4)2020 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-32252250

RESUMEN

Consumption of low-glycemic index (GI) carbohydrates (CHO) may be superior to high-GI CHO before exercise by increasing fat oxidation and decreasing carbohydrate oxidation. We compared the effects of pre-exercise feeding of a low-GI lentil-based sports nutrition bar with a high-GI bar on metabolism and performance during a simulated soccer match. Using a randomized, double-blind, counterbalanced, crossover design, participants (n = 8) consumed 1.5 g/kg available CHO from a low-GI bar (GI = 45) or high-GI bar (GI = 101) two hours before a 90 min simulated soccer match, and 0.38 g/kg body mass during a 15 min half-time break. The test involved alternating 6 min intervals of paced jogging, running, walking, and sprinting, and 3 min intervals of soccer-specific skills (timed ball dribbling, agility running, heading, kicking accuracy). Carbohydrate oxidation rate was lower during the match after consuming the low-GI compared to high-GI bar (2.17 ± 0.6 vs. 2.72 ± 0.4 g/min; p < 0.05). Participants performed better during the low-GI versus high-GI bar condition on the agility test (5.7 ± 0.4 versus 6.1 ± 0.6 s; p < 0.01) and heading (i.e., jumping height 24.7 ± 4.3 versus 22.2 ± 4.5 cm; p < 0.01) late in the soccer match (72 min). A low-GI lentil-based sports nutrition bar provides a metabolic benefit (lower carbohydrate oxidation rate) and a modest improvement in agility running and jumping height (heading) late in the test.


Asunto(s)
Glucemia/metabolismo , Carbohidratos de la Dieta/metabolismo , Índice Glucémico , Fútbol , Fenómenos Fisiológicos en la Nutrición Deportiva/fisiología , Adulto , Rendimiento Atlético , Estudios Cruzados , Método Doble Ciego , Humanos , Masculino , Recreación
9.
J Sports Sci ; 38(9): 1053-1061, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32290783

RESUMEN

The study aim was to investigate ball movement patterns using network analysis techniques, to compare between successful and unsuccessful outcomes and teams in the Australian Football League (AFL). This analysis focused on possession chains starting from a kick-in (n = 1,720), drawn from all games played in the 2015 AFL Premiership season (18 teams, 206 games). Player interactions were quantified using four network metrics: cluster coefficient, degree centrality, network density, and entropy. Three-way ANOVA with Tukey post hoc and ω2 effect sizes were calculated to assess whether differences existed between kick-in outcomes, ladder brackets, and match outcomes for each network metric. No significant differences were observed between ladder brackets or match outcomes for any network metric. More successful kick-in chains were characterised by lower density (ω2 = 0.26, large effect; F(9, 1678) = 66.6, p < 0.00) and higher entropy (ω2 = 0.17, large effect; F(9, 1678) = 39.6, p < 0.00). This suggests that chains resulting in successful kick-in outcomes exhibited lower interconnectedness, with a high number of players involved, and lower predictability in ball movement patterns. These findings have practical value for coaches and performance analysts and support further applications of network analysis in Australian football.


Asunto(s)
Rendimiento Atlético/fisiología , Conducta Competitiva/fisiología , Fútbol/fisiología , Australia , Procesos de Grupo , Humanos , Movimiento , Equipo Deportivo , Análisis y Desempeño de Tareas
10.
Braz J Med Biol Res ; 53(4): e9200, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32267309

RESUMEN

The consumption of alcoholic beverages influences carbohydrate and lipid metabolism, although it is not yet clear whether metabolism during physical exercise at different intensities is also affected. This was the objective of the present study. Eight young and healthy volunteers performed a treadmill test to identify the running speed corresponding to a lactate concentration of 4 mM (S4mM). At least 48 h later, they were subjected to two experimental trials (non-alcohol or alcohol) in which they performed two 1-km running sessions at the following intensities: 1) S4mM; 2) 15% above S4mM. In both trials, blood lactate, triglycerides, and glucose concentrations were measured before and after exercise. The acute alcohol intake increased triglycerides, but not lactate concentration under resting conditions. Interestingly, alcohol intake enhanced the exercise-induced increase in lactate concentration at the two intensities: S4mM (non-alcohol: 4.2±0.3 mM vs alcohol: 4.8±0.9 mM; P=0.003) and 15% above S4mM trial (P=0.004). When volunteers ingested alcohol, triglycerides concentration remained increased after treadmill running (e.g., at S4mM - at rest; non-alcohol: 0.2±0.5 mM vs alcohol: 1.3±1.3 mM; P=0.048). In contrast, glucose concentration was not modified by either alcohol intake, exercise, or their combination. We concluded that an acute alcohol intake changed lactate and lipid metabolism without affecting blood glucose concentration. In addition, the increase in lactate concentration caused by alcohol was specifically observed when individuals exercised, whereas augmented triglycerides concentration was already observed before exercise and was sustained thereafter.


Asunto(s)
Consumo de Bebidas Alcohólicas/sangre , Bebidas Alcohólicas/análisis , Glucemia/metabolismo , Etanol/metabolismo , Ácido Láctico/sangre , Resistencia Física/efectos de los fármacos , Adulto , Rendimiento Atlético/fisiología , Glucemia/análisis , Prueba de Esfuerzo , Humanos , Masculino , Resistencia Física/fisiología , Triglicéridos/sangre , Adulto Joven
11.
PLoS One ; 15(3): e0230179, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32155220

RESUMEN

The present study aimed to validate and compare the football-specific measurement accuracy of two optical tracking systems engineered by TRACAB. The "Gen4" system consists of two multi-camera units (a stereo pair) in two locations either side of the halfway line, whereas the distributed "Gen5" system combines two stereo pairs on each side of the field as well as two monocular systems behind the goal areas. Data were collected from 20 male football players in two different exercises (a football sport-specific running course and small-sided games) in a professional football stadium. For evaluating the accuracy of the systems, measures were compared against simultaneously recorded measures of a reference system (VICON motion capture system). Statistical analysis uses RMSE for kinematic variables (position, speed and acceleration) and the difference in percentages for performance indicators (e.g. distance covered, peak speed) per run compared to the reference system. Frames in which players were obviously not tracked were excluded. Gen5 had marginally better accuracy (0.08 m RMSE) for position measurements than Gen4 (0.09 m RMSE) compared to the reference. Accuracy difference in instantaneous speed (Gen4: 0.09 m⋅s-1 RMSE; Gen5: 0.08 m⋅s-1 RMSE) and acceleration (Gen4: 0.26 m⋅s-2 RMSE; Gen5: 0.21 m⋅s-2 RMSE) measurements were significant, but also trivial in terms of the effect size. For total distance travelled, both Gen4 (0.42 ± 0.60%) and Gen5 (0.27 ± 0.35%) showed only trivial deviations compared to the reference. Gen4 showed moderate differences in the low-speed distance travelled category (-19.41 ± 13.24%) and small differences in the high-speed distance travelled category (8.94 ± 9.49%). Differences in peak speed, acceleration and deceleration were trivial (<0.5%) for both Gen4 and Gen5. These findings suggest that Gen5's distributed camera architecture has minor benefits over Gen4's single-view camera architecture in terms of accuracy. We assume that the main benefit of the Gen5 towards Gen4 lies in increased robustness of the tracking when it comes to optical overlapping of players. Since differences towards the reference system were very low, both TRACAB's tracking systems can be considered as valid technologies for football-specific performance analyses in the settings tested as long as players are tracked correctly.


Asunto(s)
Tecnología de Sensores Remotos/instrumentación , Análisis Espacio-Temporal , Grabación en Video/instrumentación , Aceleración , Adulto , Rendimiento Atlético , Desaceleración , Fútbol Americano , Sistemas de Información Geográfica/instrumentación , Humanos , Masculino , Dispositivos Ópticos , Tecnología de Sensores Remotos/métodos , Carrera , Fútbol
12.
PLoS One ; 15(3): e0230558, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32191740

RESUMEN

PURPOSE: The aim of this study was to quantify changes in physical capacities of thirty-eight basketball players selected from different teams, as well as from varying competitive levels (i.e. Division I, Division II and Division III) during the preparation and in-season periods. METHODS: Pre (T1) and post (T2) preparation period and during regular season (T3), the players completed a Yo-Yo Intermittent Recovery test-level 1. Following a 3 to 8 days-break, players performed a 6-min continuous running test (Mognoni's test), a counter-movement jump test and a 5-min high-intensity intermittent running test. RESULTS: Blood lactate concentration measured after the Mognoni's test was significantly reduced from T1 to T2, and from T2 to T3 (P<0.001, ƞ2 = 0.424). The distance covered during the Yo-Yo Intermittent Recovery test was significantly increased only from T1 to T2 in Division II and III (P<0.001, ƞ2 = 0.789). Similarly, the physiological responses to high-intensity intermittent running test were improved only from T1 to T2 (all P<0.001, ƞ2 = 0.495 to 0.652). Despite significant changes observed in running tests from T1 to T2, at individual level 35-55% of players did not show a very likely improvement. Relative peak power produced during vertical jumps at T3 by Division I players was increased compared to T1 (ANOVA interaction, P = 0.037, ƞ2 = 0.134). CONCLUSIONS: The main improvements in physical capacities occurred during the preparation period, when the aerobic fitness and the ability to sustain high-intensity intermittent efforts were moderately-to-largely improved. However, it appears that the preparation period does not consistently impact on vertical jump variables. Aerobic fitness and force/power production during vertical jumps appear to improve across the competitive season (slightly-to-moderately). Physical tests should be used to identify weaknesses in physical performance of players and to monitor their fatigue status, with the aim to develop individualized training programs.


Asunto(s)
Rendimiento Atlético/fisiología , Baloncesto , Aptitud Física/fisiología , Estaciones del Año , Adulto , Antropometría , Humanos , Masculino , Carrera/fisiología
14.
J Sports Sci ; 38(9): 961-969, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32138596

RESUMEN

This study examined the effects of lower-body compression garments on perceived recovery and subsequent performance in basketball athletes. In a parallel-group design, 30 recreational, male basketball athletes were randomly allocated to either a control (CON, n = 15, loose-fitting clothing) or experimental group (COMP, n = 15, compression garments) for 15 h following fatigue-inducing, basketball-specific exercise in the evening (1600-1800 h). Perceptual measures of fatigue and muscle soreness, as well as physical performance tests (sprints, jumps and agility), were performed pre-exercise, post-exercise, and post-recovery (15 h following exercise). Subjective and objective measures of sleep were recorded following the exercise trial. There were non-significant (p > 0.05), unclear-trivial differences between groups for all performance measures. Perceived post-recovery fatigue (d = -1.27, large) and muscle soreness (d = -1.61, large) were significantly lower in COMP compared to CON (p < 0.05). COMP exhibited better perceived sleep quality (d = 0.42, small, p = 0.18) than CON, with an unclear difference in sleep duration between groups (p > 0.05). Wearing lower-body compression garments overnight improved perceived fatigue and muscle soreness, but had negligible effects on subsequent physical performance in basketball athletes. Future research should focus on longer periods of compression wear following fatiguing exercise.


Asunto(s)
Rendimiento Atlético/fisiología , Baloncesto/fisiología , Fatiga/prevención & control , Mialgia/prevención & control , Medias de Compresión , Adulto , Baloncesto/psicología , Humanos , Masculino , Fatiga Muscular/fisiología , Mialgia/fisiopatología , Percepción , Sueño/fisiología , Adulto Joven
15.
J Sports Sci ; 38(9): 1018-1025, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32164498

RESUMEN

This study aimed to investigate between- and within-team changes in workload [PlayerLoad (PL), training impulse (TRIMP) and session rate of perceived exertion training load (sRPE-TL)], readiness [heart rate variability (HRV)], and physical performance [20-m sprint test (including 10-m split time), countermovement jump (CMJ) and yo-yo intermittent recovery test level 1 (YYIR1)] during 3-week intensified preparation periods in female, national Under18 (n = 12, age = 18.0 ± 0.5y, stature = 180.4 ± 7.5 cm, body mass = 72.7 ± 9.3 kg) and Under20 (n = 12, age = 19.6 ± 0.8y, stature = 178.6 ± 6.4 cm, body mass = 68.0 ± 5.9 kg) basketball teams. Under18 team revealed small-to-moderate statistically significantly higher values in workload [PL: p = 0.010; ES = Small; TRIMP: p = 0.004; ES = Moderate; sRPE-TL: p < 0.001; ES = Moderate] and moderately lower readiness values (p = 0.023; ES = Moderate) compared to Under20. Within-team analysis showed no differences in workload in Under20 and statistically significant reduction (p < 0.05) in Week3 (taper period) in Under18. Pre- and post-preparation changes showed Under18 increasing only YYIR1 performance (p < 0.001; ES = Very large). Differently, Under20 statistically improved in 10-m split time (p = 0.003; ES = Moderate), CMJ (p = 0.025; ES = Moderate) and YYIR1 (p < 0.001; ES = Large). A constant adequate workload positively benefits players' readiness and physical performances during short intensified preparation periods. Conversely, using high workload with periodization strategies encompassing short overload and taper phases induced positive changes on players' aerobic performance, lower readiness values and no changes in anaerobic performances.


Asunto(s)
Rendimiento Atlético/fisiología , Baloncesto/fisiología , Acondicionamiento Físico Humano/métodos , Adolescente , Conducta Competitiva/fisiología , Prueba de Esfuerzo , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Percepción/fisiología , Esfuerzo Físico/fisiología , Carga de Trabajo , Adulto Joven
16.
J Sports Sci ; 38(9): 1070-1076, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32174252

RESUMEN

The purpose of this study was to quantify possible differences in sprint mechanical outputs in soccer according to soccer playing standard, position, age and sex. Sprint tests of 674 male and female players were analysed. Theoretical maximal velocity (v0), horizontal force (F0), horizontal power (Pmax), force-velocity slope (SFV), ratio of force (RFmax) and index of force application technique (DRF) were calculated from anthropometric and spatiotemporal data using an inverse dynamic approach applied to the centre-of-mass movement. Players of higher standard exhibited superior F0, v0, Pmax, RFmax and DRF scores (small to large effects) than those of lower standard. Forwards displayed clearly superior values for most outputs, ahead of defenders, midfielders and goalkeepers, respectively. Male >28 y players achieved poorer v0, Pmax and RFmax than <20, 20-24 and 24-28 y players (small to moderate), while female <20 y players showed poorer values than 20-24 and >24 y players for the same measures (small). The sex differences in sprint mechanical properties ranged from small to very large. These results provide a holistic picture of the force-velocity-power profile continuum in sprinting soccer players and serve as useful background information for practitioners when diagnosing individual players and prescribing training programmes.


Asunto(s)
Rendimiento Atlético/fisiología , Carrera/fisiología , Fútbol/fisiología , Aceleración , Adulto , Factores de Edad , Femenino , Humanos , Masculino , Acondicionamiento Físico Humano , Caracteres Sexuales , Adulto Joven
17.
J Sports Sci ; 38(9): 985-993, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32175825

RESUMEN

The aim of this study was to investigate the physical determinants of weightlifting competition performance based on Isometric Mid-Thigh Pull (IMTP) and Countermovement Jump (CMJ) force-time variables, in a cross-sectional and longitudinal analysis. Ten British advanced international female weightlifters' competition results and neuromuscular assessment data collected as part of the British Weight Lifting World Class Programme were utilised for the purpose of this study. All data were averaged for two consecutive 1-year periods. The cross-sectional analysis utilised the second year of data, whereas the longitudinal analysis assessed the mean change between the two years. The cross-sectional analysis results reveal IMTP Net Isometric Peak Force (PF) and CMJ Peak Power (PP) predict 94.2%, 95.1% and 91.8% of the variance in Total, Snatch and Clean & Jerk competition performance, respectively (p = <0.5). The longitudinal analysis results revealed that ∆IMTP PF was the only predicting factor of longitudinal change in weightlifting competition performance predicting 41.5%, 41.7% and 42.5% of ∆Total, ∆Snatch and ∆Clean & Jerk, respectively (p = <0.5). The assessments and equations may be utilised by coaches or sports scientists to inform the prescription of training and help predict competition performance.


Asunto(s)
Rendimiento Atlético/fisiología , Conducta Competitiva/fisiología , Contracción Isométrica/fisiología , Músculo Esquelético/fisiología , Levantamiento de Peso/fisiología , Adulto , Estudios Transversales , Prueba de Esfuerzo , Femenino , Humanos , Estudios Longitudinales , Músculo Esquelético/inervación , Ejercicio Pliométrico , Muslo , Adulto Joven
18.
J Sports Med Phys Fitness ; 60(2): 236-243, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32125125

RESUMEN

BACKGROUND: Previous studies were limited to physical measurements or included very few performance test batteries, which has hindered the determination of the best tests for predicting competition performance in weightlifters. This study aimed to examine the relationships between body composition, Wingate anaerobic power, vertical jump height, isokinetic strength, handgrip strength, trunk strength, and competition performance and to determine the best predictors of competition performance in male junior weightlifters. METHODS: Sixty-seven male junior weightlifters (age 16.6±1.5 years, height 166.6±5.2 cm, body mass 67.0±9.3 kg) voluntarily participated in this study. After a national weightlifting competition, the participants were evaluated for anthropometric measurements, Wingate anaerobic power, isokinetic strength, vertical jump, handgrip strength, and trunk strength tests. The competition performance of the participants was calculated using the Sinclair equation and used as the dependent variable in statistical analysis. RESULTS: The correlations between the variables calculated from the five strength-power tests and the Sinclair score were significant (r=0.448 to 0.951, P≤0.05). The regression model suggested that the best predictors of weightlifting performance were Wingate mean power, the countermovement jump with arm swing, and body fat percentage, which accounted for approximately 88% of the common variance associated with competition performance in male junior weightlifters. CONCLUSIONS: The results of this study showed that the predictors of weightlifting performance were Wingate mean power, countermovement jump with arm swing, and body fat percentage.


Asunto(s)
Rendimiento Atlético/fisiología , Composición Corporal/fisiología , Levantamiento de Peso/fisiología , Adolescente , Prueba de Esfuerzo/métodos , Fuerza de la Mano/fisiología , Humanos , Masculino
19.
PLoS One ; 15(3): e0229440, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32126107

RESUMEN

Actually, there is scarce literature looking for the relationship between inter-limb asymmetries and performance in youth elite team sports. The main purpose of this cross-sectional study was to examine the relationships between inter-limb asymmetries and physical performance in youth elite team-sports players. A secondary objective was to evaluate the presence of between-sexes differences in inter-limb asymmetries in elite youth team sports players. Eighty-one young elite team-sports athletes (age: u-14 to u-18) performed the star excursion balance test in the anterior direction (SEBT ANT), a single leg vertical countermovement jump test (SLCMJ), the one leg hop test for distance (OLHT), a 30 m sprint test, and the V-cut test. Inter-limb asymmetries were calculated for SEBT ANT, SLCMJ and OLHT. Pearson r was used to analyse the relationships between inter-limb asymmetries and physical performance. Results showed significant (p < 0.05) but small (r = 0.26) relationships between SLCMJ asymmetries and 30 m sprint time for the total group. Significant negative correlations with small to moderate magnitude of correlation were also found between SLCMJ asymmetries and SLCMJ performance on the lowest performing limb for the total group (p < 0.05; r = -0.26), males (p < 0.01; r = -0.48) and females (p < 0.05; r = -0.30). Moreover, significant negative correlations with moderate and large magnitude were also present between OLHT asymmetries and OLHT performance on the lowest performing limb for the total group (p < 0.01; r = -0.44), males (p < 0.01; r = -0.56) and females (p < 0.01; r = -0.64). No correlations were observed between asymmetries and either the V-cut test or SEBT ANT performance. No correlation were observed between SEBT ANT asymmetries and physical performance. In addition, when comparing asymmetry values between sexes there were no significant differences in vertical (p = 0.06) and horizontal (p = 0.61) jumping tests. However, there were significant differences in asymmetry between sexes in the ANT SEBT (p = 0.04). In conclusion, the current study indicated that jumping asymmetries were associated with decrements in sprint speed and jumping performance. Therefore, assessing inter-limb asymmetries would be recommended to improve training interventions for youth elite team-sports athletes.


Asunto(s)
Rendimiento Atlético/fisiología , Prueba de Esfuerzo/métodos , Pierna/fisiología , Adolescente , Estudios Transversales , Femenino , Humanos , Masculino , Equilibrio Postural , Caracteres Sexuales , Deportes Juveniles/fisiología
20.
PLoS One ; 15(3): e0230133, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32214322

RESUMEN

This study examines the relative age effect (RAE) and its impact on the performance of elite male (n = 3,358) and female (n = 3,273) handball players in the U-19 (n = 2,188), U-21 (n = 2,031), and senior (n = 2,412) categories of the 2013/2014, 2015/2016 and 2017/2018 World Handball Championships organised by the International Handball Federation (IHF). The distribution of the players´ birth dates (by quartile: Q, and semester: S) by categories, handball playing positions, and membership of continental federations, were analysed for each of the three two-year periods in which the World Handball Championships took place. Differences between the observed and expected birth dates were tested using a chi-square goodness of fit test, and subsequent calculations were tested using odds ratios. The Spearman's correlation coefficient was applied to test the correlation between the relative age of the athletes and (their) performance parameters. The results revealed a prevalence of the RAE on both male and female in the U-19 and U-21 categories (p<0.001), and a stabilisation of the RAE throughout the period analysed (2013/14-2017/2018). The RAE was not found in the female senior category (2013, 2015 and 2017) or male senior category (2013) (p>0.05). All playing positions were impacted by the RAE (p<0.001), and especially strong effect sizes were noted for male pivots (Vc = 0.66/0.68/0.60) and female center backs (Vc = 0.71/0.65/0.71). In our analysis of the handball continental federations, the RAE was found in all regions, except Oceania (p>0.05). The RAE also affected athlete performance: the oldest athletes played more minutes and achieved better performances. The RAE was associated with the final placement of the teams in each championship category, except in the male youth category. The findings clearly demonstrated that the RAE has a significant impact on the selection of male and female athletes to international competitions and the performance of both men and women in international handball. The potential implications of these findings for policy and practice are discussed.


Asunto(s)
Factores de Edad , Rendimiento Atlético , Adolescente , Atletas , Femenino , Humanos , Masculino , Estadísticas no Paramétricas
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